Network switches and other network elements often buffer incoming data packets in memory before forwarding the packets to their destinations. Some switch configurations use shared memory. For example, U.S. Patent Application Publication 2006/0155938, whose disclosure is incorporated herein by reference, describes a shared memory having a plurality of receive ports and a plurality of transmit ports characterized by a first data rate. The memory includes a plurality of memory banks organized in rows and columns, and operation of the memory array is characterized by a second data rate. Buffering is operable to decouple operation of the receive and transmit ports at the first data rate from operation of the memory array at the second data rate.
U.S. Patent Application Publication 2011/0058571, whose disclosure is incorporated herein by reference, describes a communication apparatus that includes a plurality of switch ports. Each switch port includes one or more port buffers for buffering data that traverses the switch port. A switch fabric is coupled to transfer the data between the switch ports. A switch control unit is configured to reassign at least one port buffer of a given switch port to buffer a part of the data that does not enter or exit the apparatus via the given switch port, and to cause the switch fabric to forward the part of the data to a destination switch port via the at least one reassigned port buffer.